This custom Subaru Legacy named the GTk Concept build by Specialized Vehicles, Inc. (SVI) under Subaru’s specifications is designed to test the sportiness limits of a wagon. 
This one-of-a-kind SVI Subaru Legacy GTk accommodates an intercooled and turbocharged 2.5-liter engine under the bonnet with an optimized ECU, producing 300 HP (350 lb.-ft. of torque), 35 HP extra than the stock version, witch is linked to the new 6-speed manual transmission found in the 2010 Legacy 2.5GT Sedan.
The SVI Subaru Legacy GTk also comes with a ‘Track-ified’ chassis that uses a SPT strut tower brace and a lowered suspension plus the extra engine power is now harnessed by the 6-piston monobloc calipers front brakes and 4-piston calipers rear brakes.
The HRE 19 inch Comp wheels wrapped in BF Goodrich offer perfect traction for the SVI Subaru Legacy GTk and so far no pricing details have been released regarding the complete list of modifications. 
Subaru press release :
If a turbocharged, lowered, beefed-up Subaru sport wagon sounds like a great car for taking to the track for some autocross action, then wait until you open the rear liftgate. In the generously sized cargo area, you’ll find a Coyote Motorsports XP kart (the "k" in GTk), also ready for track duty — in
this case, SCCA Solo autocross. The Subaru Legacy GTk is a car you can drive to the autocross track, and then compete against your kart-driving teenager in a handicapped point system on the same track — with no trailer necessary.
The one-of-a-kind Legacy GTk, constructed to Subaru’s specifications by Specialized Vehicles, Inc. (SVI), probes the outer limits of what a sport wagon can be. The GTk Concept combines the power and presence of a performance-tuned Legacy with the cargo capacity of the all-new 2010 Outback. The cargo area is large enough to haul a complete race kart, which weighs about 160 lbs. with engine and ready to race.
SVI worked with other suppliers to integrate individual sub-systems and components. Developed by JAC Products with input from Subaru, the roof cargo management hardware on the Legacy GTk wagon provides a sleek profile while offering a fully functional cross bar system. The liftgate spoiler, midgate
spoiler and blackout-style HID headlights were sourced from the Japanese domestic market (JDM) Legacy. SVI applied its own custom parts, including a front air dam with fog lights; lateral hood vents; custom window tint, and, at the rear, smoked tail lights and a diffuser. The final touch from SVI is a
custom black-over-red paint scheme.
Subaru Turbo Boosted to 300 HP
The Legacy GTk powertrain, including the new 6-speed manual transmission, is borrowed from a 2010 Legacy 2.5GT Sedan. With a modified exhaust system and reprogrammed ECU — but no bolt-on performance parts — the 2.5-liter turbocharged and intercooled engine produces 300 hp and 350 lb.-ft. of torque, up from the stock model’s 265 hp and 258 lb.-ft.
The Legacy GTk draws from the Subaru Performance Tuning (SPT) and STI catalogs. An SPT short-throw shifter with STI shift knob controls the 6-speed. The Continuous version of the Symmetrical All-Wheel Drive system uses a viscous coupling locking center differential. The system splits the torque 50:50 and can transfer more power to the wheels with the best traction.
SVI built a custom quad-tipped exhaust system for the Legacy GTk, giving the Subaru Boxer growl a track-inspired tone. Under the hood, the engine compartment is dressed out with braided stainless hoses and brake lines and SPT anodized aluminum parts.
Track-ified Chassis
Bolt-on chassis mods make the Legacy GTk is track-ready, starting up front with an SPT strut tower brace. Suspension is lowered using Bilstein(®) struts and suspension calibration, along with STI "pink" springs. A full Brembo(®) brake upgrade uses 6-piston monobloc calipers in front with 355 x
32 mm 2-piece floating cross-drilled discs and billet aluminum hats. The rear setup is the same, but with 4-piston calipers. Getting the power to the pavement are BF Goodrich P245/50 R19 Force-KDW 2 tires mounted to HRE custom 19-inch Comp wheels.
Custom Interior and "Garage" are Enviro-friendly
Driving a track car is no cause to forgo comfort, convenience and onboard entertainment. The Legacy GTk interior combines fun and functional. Coming under the "functional" banner is the custom-made "kart friendly" cargo area with rubber decking, tie-down points, and LED lighting. Under the "comfort"
column, there is a full custom Ultrasuede(®) and leather trimmed interior, including Recaro(®) Sportster custom front seats and custom matching rear seats.
The maker of Ultrasuede, Toray, employed its latest EcoDesignâ„¢ product to comply with Subaru of America’s policy to minimize waste. (The Subaru of Indiana Automotive plant that builds Legacy, Outback and Tribeca models has achieved Zero Landfill status.) The EcoDesign product is made using
100-percent recycled Ultra Microfibers; the base material comes from the manufacturer’s post industrial-sourced polyester film.
The Legacy GTk instrument panel and doors feature carbon fiber patterned trim. Custom boost, temperature and oil pressure gauges provide vital engine information, and STI aluminum pedals add a rally car feel.  The harman/kardon(®) custom surround-sound audio system drives 18 speakers with
an 11-channel high efficiency GreenEdge processor/amplifier. Compared to conventional mobile audio systems, harman/kardon GreenEdge components are lighter and consume less power to produce even higher acoustic output levels.  The system is controlled by a harman/kardon AM/FM/XM/single-CD head unit with a 7-inch touch-screen display.
The Kart: Fully Functional, Ready to Race
Subaru designed the Legacy GTk as a fully functional vehicle. The idea was to build a car that would facilitate family racing fun. In this case, the GTk also highlights a motorsport that enables a parent to compete against his/her teenager in the same venue — a rarity in any sport.
Since no trailer would be used, Subaru chose a kart that would not only fit into the cargo area, but would be suitable for a child old enough to ride in the front seat, in compliance with child seating laws. The SCCA Junior Driver kart program offered just that opportunity, its Formula Junior A class
specifically intended for the 12-15 age bracket. Built by Coyote Motorsports in Spencerport, N.Y., the XP kart is powered by a Yamaha KT-100 two-stroke engine and can reach up to 50 mph in SCCA Solo racing and up to 120 mph in road racing.

Source: Subaru